| 摘要 |
PURPOSE: An apparatus for generating a tracking error signal is provided to adjust a tracking of a light pickup device accurately. CONSTITUTION: The first adder inputs main beam signals(A,B,C,D) detected from a light detecting device of a light pickup device and adds inputted A signal and B signal. The second adder adds the inputted B signal and D signal. Signal compensating units amplifies the outputs of the first adder and the second adder into a size of signal capable of performing a signal processing at a rear portion. High pass filters inputs the outputs of the signal compensating units and outputs a DC voltage in accordance with a peak value of an inputted high frequency envelope signal. Comparators compares the output of the high pass filters with a reference signal and outputs a pulse signal. The outputs of the comparators are inputted to a phase detecting unit(27'), and a correlation in accordance with a phase of two input signals is detected, and if a phase difference more than an inherent phase difference of the two signals is generated, the phase difference is removed. The phase detecting unit(27') includes a correlation detecting unit(30) inputting output signals of the comparators and detecting a correlation of two signals. The correlation detecting unit(30) generates a mute signal if a phase difference more than an inherent phase difference of the two signals is generated. The phase detecting unit(27') includes a phase detecting unit(35) inputting the outputs of the comparators and comparing phases of the two signals and outputting a difference signal. The phase detecting unit(27') includes a mute processing unit(40) inputting a phase difference signal from the phase detecting unit(35) and removing and outputting a phase difference signal of a portion where a mute signal applied based on a control of the correlation detecting unit(30) and outputting a phase difference signal as it is when a mute signal is not applied.
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